Analysis of natural products by SFC – Applications from 2015 to 2021
Markus Ganzera, Michael Zwerger
Abstract
Complexity and variability in composition are major challenges associated with the analysis of natural products in biological matrices like plant extracts. To indicate and confirm that SFC is an excellent analytical technique to investigate such samples, is the aim of this review. It is shown that in recently published manuscripts the range of successfully assessed compounds was very wide, including compounds of variable polarity (lipids, flavonoids, saponins, terpenes) or acidity/alkalinity (phenolic acids, alkaloids), not to forget chiral separations required for a meaningful characterization of e.g. cannabinoids. This versatility in target analytes is possible because of the flexible nature of SFC, being compatible with different stationary phase chemistries (silica, reversed phase or chiral materials, HILIC) and detection modes (DAD, MS, ELSD, ECD). The online coupling to SFE, allowing simultaneous extraction and analysis of a sample, is a relatively new technical option and addressed as well. Divided by different compound classes, this review reports on the range of separation and detection conditions that have been described for natural product analysis by SFC from 2015 till date; limitations and advantages of individual assays are discussed and compared to related studies. By considering both, “standard” as well as innovative/uncommon applications, the current status and future perspectives of this emerging separation technique are highlighted.